第5章开放的经济顾炜宇资料.ppt

* In the equation, ε is the only endogenous variable; hence this equation determines its value. * *** Note *** At the lower left corner of this graph, NX does NOT NECESSARILY EQUAL ZERO!!! * WARNING: Don’t let your students confuse the demand for dollars in the foreign exchange market with demand for real money balances (Chapter 4), or the supply of dollars in the foreign exchange market with the supply of money (Chapter 4). If you and your students are into details: NX is actually the net demand for dollars: foreign demand for dollars to purchase our exports minus our supply of dollars to purchase imports. Net capital outflow is the net supply of dollars: The supply of dollars from U.S. residents investing abroad minus the demand for dollars from foreigners buying U.S. assets. * * * * Suggestion: Have your students do this experiment as an in-class exercise. Have them take out a piece of paper, draw the graph, then show what happens when there’s an increase in the country’s investment demand (perhaps in response to an investment tax credit). * The analysis here applies for import restrictions (tariffs, quotas) as well as export subsidies. * In the text box, the remarks in parentheses after each result provide an abbreviated explanation for that result. The real exchange rate appreciates, because the quota has raised the net demand for dollars associated with any given value of the exchange rate. But the equilibrium level of net exports doesn’t change, because the supply of dollars in the foreign exchange market (S-I) has not been affected by the trade policy. (Remember, S = Y-C-G, and the trade policy does not affect Y, C, or G; the policy also does not affect I, because I = I(r*) and r* is exogenous.) The appreciation causes exports to fall. And, since exports are lower but NX is unchanged, it must be the case that IM is lower too, which is what you’d expect from a trade policy that restricts imports. * * It’s important here for st